The 24th Congress of the Spanish Society for Microbiology (SEM) took place on 10-13 July, 2013 at the Bellvitge Campus of the University of Barcelona (UB), in L'Hospitalet de Llobregat, Barcelona [http://congresosem2013.semicro-biologia.org](Fig. 1). This meeting brought together 618 microbiologists from several prestigious universities and research centers throughou Spain, as well as experts from 24 countries including the United States, the United Kingdom, Germany, Australia, Canada, France, Italy, Belgium, Mexico, Austria, Chile, China, Denmark, Slovenia, the Netherlands, Peru, Sweden, Scotland, Turkey, Uruguay, and Venezuela.